This study investigates the effect of recombinant human growth hormone on final adult height of children who do not meet the criteria of "classic" growth hormone deficiency. These children may have some degree of growth hormone deficiency and demonstrate severe growth retardation. Subjects accepted into this study were children or prepubertal teenagers who had height 2 SDs below the mean, who were in good health and had a normal growth hormone response to provocative testing. We studied six children at our center. Patients for the first year were either treated or untreated control. After the first year, they were randomized to a.d. vs t.i.d. treatment to be followed to final height. There is a sub-study in this protocol. Genentech is looking at growth hormone binding protein levels and at growth hormone receptor defects. We had a total of 6 patients in this study. Our last patient was seen in January for his final visit. During his 8 years on treatment, he grew 43.6 cm, an average yearly rate of 6.2 cm. Three other patients were treated until final heights; grew well at an average annualized rate of 6.5 cm to 7 cm. A fifth patient discontinued the study to receive daily injections. (He was in a 3 x/week group). Our sixth patient stopped treatment in 1988 because of fear of leukemia.